Learning to play music is an embodied process, but traditional tools like scores and recordings overlook the role of gesture. While video tutorials offer visual cues, they remain detached from the instrument. We present ReTouche, an interactive system that projects synchronized notes and hand gestures directly onto the actuated keys of a player piano. The system includes a pipeline for adapting publicly available overhead-view YouTube videos and supports interactions for video-based learning, such as sectional practice, layered guidance, and self-recording. We evaluate ReTouche through a comparative structured observation study with YouTube-based self-learning (n=18), a two-week autoethnography study (n=3), and a focus group with professional piano teachers (n=4). Our findings show that embodied representations can ground self-guided piano learning by anchoring gesture, sound, and action within the instrument. Learners appropriated these representations to develop strategies and sustain motivation, while teachers saw potential for integrating ReTouche as a complement to conventional pedagogy.

Data visualization benefits from non-visual cues to enable people to understand information by engaging with it through multimodality, yet most approaches rely on cumbersome technologies or large scale artifacts, making them difficult to adapt to dynamic or complex datasets. In this paper, we explore the use of cutaneous haptics as a lightweight quantitative channel for visualization tasks, allowing users to feel data and interact with it dynamically. We present Haptixel, an open-source DIY encountered-type wearable providing force-feedback on the users’ fingertips’ pulp. We propose an interaction framework illustrating how Haptixel can be used to complement visualization tasks through combinations of force levels and contact types. We evaluate our approach in a pixel-art-like VR user study (n=16) where pixels color/height are associated to forces as a univariate value mapping. Results show that participants can retrieve information with Haptixel, and significantly discriminate 3D-data with at least four levels of forces; suggesting that cutaneous force-feedback can function for quantitative distinctions in visualization tasks.